While President Bush was stitching together his justly praised alliance against Saddam Hussein, problems ahead were signaled by a televised talk Saudi Arabia's Crown Prince Abdullah delivered to his troops at the front.

In words the Israeli Embassy here has spread widely across Capitol Hill, the crown prince gave potentially valuable ammunition to congressmen preparing to fight the new U.S. arms sale to Saudi Arabia. The "fearless Iraqi army and all the Arab armies" are "brothers at arms" who are "striving to regain the plundered rights in Palestine" -- after restoring Kuwait to the al-Sabah dynasty.

Abdullah intended to make a distinction between the feared Saddam and his fearless soldiers, but his words will be exploited in the uphill congressional battle against Bush's Saudi arms sale. That is a sign that the president's consensus on the Persian Gulf crisis is splintering even as he approaches a fateful decision on what to do with the American desert army.

Other signs abound that Bush's smooth sail through the Gulf has ended. An Iran-Iraq economic deal shriveling the anti-Iraq embargo is probable, and the Chinese are bargaining with Baghdad. Rising concern is seen in both Europe and among U.S. voters that Bush may have trapped himself in a cul-de-sac from which war or American retreat is the only exit.

Bush's promise to King Fahd of Saudi Arabia to sell $20 billion in new American arms, revealed on Capitol Hill by Saudi Ambassador Prince Bandar, is driving a wedge through his bipartisan political support. Pro-Israel critics of the huge sale are mapping plans to split the package in half. Besides infuriating the Saudis, that would raise questions worldwide about where the United States really stands.

What popular Prince Bandar told members of the House Foreign Affairs Committee in a closed-door chat Sept. 13 almost spun the roof off the Capitol. "To use this crisis as a fig leaf to reorder the military balance of power in the Middle East and rush it through Congress," Rep. Mel Levine, a leader of the pro-Israel bloc, told us, "is a grave tactical mistake. It raises serious political concerns."

One pro-Israel House Democrat, impeccable in supporting Bush up to now, told us privately that the arms sale would "erode" Bush's strong backing and eventually "destroy" the political consensus. The deal provides an opening for attack or, at the least, a rationale for expressing grave misgivings about a policy many American voters still do not understand.

Unscientific indicators -- radio call-in programs and congressional mail -- suggest popular support is declining rapidly for a policy that could result in unnecessary war. Critics of the president's policy such as Zbigniew Brzezinski, President Jimmy Carter's national security adviser but a Bush backer in the 1988 campaign, routinely get warm receptions. Speaking in the Navy town of Norfolk Tuesday evening, Brzezinski received a standing ovation after referring to military projections of a war-winning "surgical strike" on Baghdad as "ridiculous" and "totally senseless."

As for Bush's remarkable international support, Western diplomats in Washington believe it peaked in the outrage over Saddam Hussein's inexplicable and costly crackdown on Western embassies in Kuwait, as dramatically illustrated in French President Francois Mitterrand's public anger over that incident.

But French diplomats here warned not to read that anger as support for a war policy. To the contrary, what Mitterrand and many European leaders fear most is that Bush's anti-compromise, anti-mediation adamancy may leave him and his allies no alternative but war.

U.N. sanctions are under assault from two sources: Iran and China. Tehran is moving quickly toward trading its foodstuffs for crude oil products refined in Iraq. Beijing is pondering undercover trade deals to set itself up for preferential oil treatment when the Gulf crisis ends.

After two months, such cracks abroad and at home in the grand anti-Iraqi alliance are inevitable. But the president's critics, increasing perhaps faster than he thinks, are nearing the point where outright opposition is beginning to look better than blind support.